1. Field of the Invention
The present invention relates to a position detection apparatus for receiving a light emitted from a light source and detecting the position of the light source and remote control apparatus for remote controlling a reception unit from a transmission unit having a light source and an ON/OFF switch.
2. Description of the Prior Art
Conventionally, there is provided a so-called cordless remote control unit for controlling at a distance an apparatus such as a television apparatus, a video tape recorder, a video disc player, a compact disc (CD) player, an audio tape recorder and the like.
The aforementioned remote control unit consists of: a transmission unit having an operation block where pushbuttons are arranged to be operated by a user and a light injection block for modulating a data entered by the user through a pushbutton, using a light such as infrared rays as a medium to be injected; and a reception unit for receiving the light injected from the transmission unit and demodulating the light so as to carry out a corresponding operation. The transmission unit and the reception unit are electrically separated from each other and normally used at spatially distant positions.
FIG. 1 schematically shows the aforementioned transmission unit 10. The transmission unit 10 has a casing of an approximately flat rectangular parallelepiped shape. This casing has a size convenient to be grasped by a hand of the user and has a main surface where an input operation block 11 and a plurality of pushbuttons are arranged. Moreover, a light injection block 13 is provided one of the faces opposing in the longitudinal direction of the casing of the transmission unit 10 so as to inject light in the longitudinal direction.
FIG. 2 schematically shows the aforementioned reception unit. The reception unit 20 is provided in a television image receiving apparatus and having a light detection block 72 arranged below a display block 27 for receiving and demodulating the light injected from the aforementioned transmission unit 10 so as to carry out a function selected by the operation of the operation block 11 of the transmission unit. For example, the channel of the television image receiving apparatus is changed from one to another or the sound volume is increased or decreased.
On the other hand, in a personal computer, a video game apparatus and the like, a pointing device is provided for specifying a position on a display screen such as CRT and a liquid crystal panel for selecting a function.
As the aforementioned point device, a mouse is provided. The mouse has a size convenient to be wrapped by a palm of a hand and can be moved on a flat surface such as a desk, and corresponding to the position of this mouse, a specified position is indicated by a cursor or the like on the aforementioned display screen. The mouse has one to three pushbuttons on the casing for entering an instruction such as selecting a function at the specified position.
Moreover, as the pointing device used for a video game apparatus, there is provided a unit having a casing on which an up, down, left, and right button and a pushbutton are arranged. In such a device, the aforementioned specified position is shifted by pressing the up, down, left, and right buttons and the distance to be shifted is adjusted by the length of time the corresponding button is kept pressed. A selection at the aforementioned specified position is carried out by pressing the pushbutton.
Furthermore, as the pointing device, there is provided a joystick. The joystick consists of a single lever which is supported by a gimbal mechanism. When the lever is inclined, according to the inclination direction and inclination angle, the aforementioned specified position indicated by a cursor or the like is moved on the aforementioned display screen. Moreover, in a case when the joystick is provided with a selection pushbutton, a function can be selected at the aforementioned specified position.
Here, FIG. 3 shows a joystick 100 disclosed in Japanese Patent Laid-Open Sho 61-276014 which has a light source block arranged on the lever 101 and having a light source 102, and a light reception block having a lens 103 for receiving the light injected from this light source block and a two-dimension light receiving element 104 for detecting the light.
The aforementioned joystick 100 is arranged as a unitary portion of a casing having approximately cubic configuration. The light source 102 is arranged at the lower end of the lever 101 and emits a light which is converged by the aforementioned lens 103 onto the aforementioned tow-dimensional light receiving element 104. This two-dimensional light receiving element 104 detects an operation of the lever 101 according to the position where the light is converged. Moreover, the joystick 100 moves the specified position indicated by a cursor or the like on the display screen according to the direction and the angle of the tilting of the lever 101.
So-called audio visual (AV) apparatuses such as a television image receiving apparatus, a video tape recorder, a video disc player, a CD player, and an audio tape recorder as well as personal computers and video game apparatuses are widely used by various users.
Since these apparatuses have a variety of functions and for an ordinary user having no technical knowledge, it may appear too much complicated to operate such apparatus. Moreover, because of the limit of the operation block, these apparatus may not exhibit sufficiently their functions available.
For example, in a so-called remote control unit used for operation of the aforementioned apparatuses at a distance, there should be a number of pushbuttons in order to sufficiently operate the function of the reception unit 20 which may be, for example, a television apparatus. However, if the number of pushbuttons is increased, the user cannot select the necessary one without taking time and care.
Moreover, in the case of the aforementioned mouse, it is necessary to provide a flat plane for operation of the mouse and to connect the mouse through a cord. There has been provided a so-called optical mouse which does not require a cord for connection, but the optical mouse requires a mouse pad dedicated to the optical mouse. Thus, the mouse including the optical mouse is inconvenient in comparison to the aforementioned remote control unit.
Moreover, in the unit having the up, down, left, and right buttons and the select buttons arranged on a casing, it is necessary to operate the four buttons and the select buttons. This cannot be said to be good in operationability.
Moreover, in the aforementioned joystick, a position is selected according to the direction and the angle of the lever provided on the joystick. That is, it is necessary to tilt the lever at a particular angle to move the specified position on the display, operation cannot be said to be easy and requires some training.